The invention relates to a heat exchanger for two fluid media, especially liquids, having a housing which can be closed with a cover, and which has inlets and outlets for the two media, and a core for the separate carrying of the two media under heat exchange, at least the core being able to be manufactured as a die-casting.
A heat exchanger of the kind referred to is described in an older proposal of the Applicant (Patent Application No. P 35 42 721.3). In this heat exchanger the passages for carrying the two media are formed in a core which can be made by die casting, and in their height these passages extend over the entire height of the core. For an effective heat exchange, the walls of the passages must be as thin as possible, and the width of the passages, i.e., the distance between adjacent walls, must be as small as possible, since only in this manner are advantageously short heat conduction paths achieved. In the heat exchanger according to the above-referenced older proposal, there is the great disadvantage that if the requirement just described is satisfied, the core is difficult to manufacture or cannot be manufactured economically. This is due to the fact that the ratio of the wall height to the wall thickness or wall spacing is very great, and that therefore the distances over which the molten metal must run and the depth from which the casting must be drawn to extract it from the mold (mold stripping length) becomes very great. In the casting process it can very easily happen that the mold is not entirely filled, resulting in a high rate of rejection. The great mold stripping lengths require greater force in the stripping of the castings, which entails the danger of damage to the thin-walled casting and hence also an increase in the number of rejects.
The problem therefore presents itself of creating a heat exchanger of the kind specified above, which will avoid the recited disadvantages and which especially will have desirable casting characteristics. Furthermore, an effective heat exchange between the two media is to be assured, and the heat exchanger is to be adaptable in a simple manner to different applications.